The present invention relates to an apparatus and a method for detecting a foretoken of abnormality in a plant such as a power plant and issuing an alarm in good time.
A point value (sensor reading) is defined in advance for close surveillance in conventional power plants in order to detect any abnormality in the plant. Then, the latest plant data is compared with the upper and lower limit values defined for the point value and the plant is determined to be in an abnormal condition when the data is out of the limit values (refer to Japanese Patent Publication No. 2,772,179, the entire contend of which is incorporated herein by reference).
With the above-described technique, time is required for plant operators to cope with the situation where the plant is currently being operated and if an abnormal condition of the plant is detected by referring to the point value for close surveillance. In other words, abundant knowledge and experiences of skilled power plant operators are required to define optimum upper and lower limit values. Then, the plant may need to be repeatedly subjected to test runs and the upper and lower limit values may have to be altered for a number of times at the cost of time and labor on the part of such skilled power plant operators.